1. Field of the Invention
The present invention relates to fuel filter/dryer for incorporation in the fuel system supplying a fuel consuming device such as an engine, heater, burner, furnace, etc.
2. Description of the Prior Art
Fuel systems in almost all motor vehicles, incorporate at least one particulate filter to filter out fine particles from the fuel flowing through the fuel system. Such fine particles could have disastrous consequences for the operation of the engines in motor vehicles because they can potentially obstruct the narrow passages in fuel injectors and/or carburetors; and if these particles do find their way into the engine, they can cause unnecessary wear and damage to engine parts. In addition to being contaminated by particulate matter, commercially sold fuel is also contaminated with water. This water presents a problem especially in winter time, because it can lead to fuel line freeze-up. Fuel additives are currently available on the market, which are added directly to the fuel in the fuel tank in order to xe2x80x9cdryxe2x80x9d the fuel. These additives however get consumed along with the fuel, and may adversely affect the performance of the engine and or shorten engine life. The present invention combines a particulate filter with a desiccant that remains separate from the fuel. Therefore, the present invention provides the benefits of removing particulate matter and water from the fuel, without adversely affecting the performance obtained from the fuel. None of the prior art shows the combination of a fuel filter and a bed of granular desiccant material in a single unit. Further, none of the prior art shows the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 2,536,274, issued to Richard S. Gaugler Jan. 2, 1951, shows a desiccant cartridge for use refrigeration equipment. The desiccant cartridge of Gaugler made of desiccant granules contained in a woven mesh sleeve Gaugler does not show the combination of a fuel filter and desiccant bed in a single unit.
U.S. Pat. No. 3,029,581, issued to Hugh C. Robbins on 20 Apr. 17, 1962, shows a desiccant cartridge having an inner tube located concentrically within an outer tube. The desiccant housed in the inner tube and is held in place by wads of glass-wool referred to as filter discs. The desiccant cartridge of Robbins is intended for drying gases. Robbins does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Robbins does not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 3,246,758, issued to William Wagner on 5 Apr. 19, 1966, shows a plug with a viewing window and a chemical moisture indicator used for determining the moisture content of a desiccant material. Wagner does not show the combination of a fuel filter and a desiccant bed in a single unit.
U.S. Pat. No. 3,505,783, issued to Harold E. Graham on 10 April 14, 1970, shows a transparent cylindrical housing containing an xe2x80x9cadsorbentxe2x80x9d material. Graham does not show the combination of a fuel filter and a desiccant bed in a single unit.
U.S. Pat. No. 3,705,480, issued to Wallace M. Wireman on Dec. 12, 1972, shows a desiccant cartridge having a filter in series with a color-changing desiccant bed. The desiccant cartridge of Wireman is intended for drying gases. Wireman does not show the combination of a liquid fuel filter and a desiccant bed in a single unit. Further, Wireman does not show the system of baffles and mesh screens used in the present invention:
U.S. Pat. No. 3,724,177, issued to George A. Grote on Apr. 3, 1973, shows a cartridge for filtering gases. The cartridge of Grote includes a bed of pulverulent material positioned between layers of cotton. Grote does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Grote does not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 4,236,902, issued to Roy A. Fricke on Dec. 2, 1980, shows an air purifying apparatus having a filter and a bed of absorber material. The absorber material of Fricke is intended to remove pollution such as tobacco smoke from the air and is not a drying agent. Fricke does not show the combination of a fuel filter and a desiccant bed in a single unit.
U.S. Pat. No. 4,259,097, issued to Amrut R. Patel et al. 10 on March 31, 1981, shows an oil and desiccant filter for a gas. Patel et al. do not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Patel et al. do not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 4,746,338, issued to Clifford C. B. Williams on May 24, 1988, shows a gas filter having a first section which contains a desiccant and a second section which contains activated charcoal. Williams does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Williams does not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 4,853,123, issued to Mark B. Hays et al. on Aug. 1, 1989, shows a fuel filter having micron sized pores that filter out aqueous and particulate contaminants. Hays et al. do not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Hays et al. do not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 5,017,285, issued to Leon P. Janik et al. on May 21, 1991, shows a fuel filter having a two stage filter, with the second stage acting as a water barrier. The trapped water is collected in a sump. Janik et al. do not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Janik et al. do not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 5,879,543, issued to Bijan Amini on Mar. 9, 1999, shows a filter element composed of non-metallic material and water sensor used to detect presence of water in the fuel, which generates a signal that engages a pump to remove a quantity of separated water from the filter housing. Amini does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Amini does not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 5,916,442, issued to David Paul Goodrich on Jun. 29, 1999, shows a fuel filter assembly for removing water from a fuel under pressure with a filter media positioned within sleeve members. An accumulation chamber and an outer valve provide the ability to drain unwanted fluid from the fuel. Goodrich does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Goodrich does not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 5,993,675, issued to Albert P. Hagerthy on Nov. 30, 1999, shows a filter for separating water from fuel in marine and diesel engines. The filter elements are constructed from multiple adjacent microfibers layers bonded to each other which allows the passage of fuel while substantially limiting the passage of water. Hagerthy does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Hagerthy does not show the system of baffles and mesh screens used in the present invention.
U.S. Pat. No. 6,224,439, issued to Sato, et al. On May 1, 2001, shows a fuel filter having a water accumulation detection ability. The water detecting mechanism is placed under the filter body made of transparent material. Sato at al. Do not show the combination of a fuel filter and desiccant bed in a single unit. Further, Sato et al. do not show the system of baffles and mesh screens used in the present invention.
European Patent Application Number 0 162 022 A2, by Maria Cristina Cantoni dated Nov. 21, 1985, shows an air filter for automotive air conditioning units. Cantoni does not show the combination of a fuel filter and a desiccant bed in a single unit.
United Kingdom Patent Document Number 343,105, by Richard Lant et al. dated Mar. 12, 1931, is directed to the use of higher fatty acid esters of cellulose as a filter material for removing water from organic liquids. Lant et al. do not show the combination of a fuel filter and a desiccant bed in a single unit
United Kingdom Patent Document Number 971,230, by Hugh C. Robbins dated Sept. 30, 1964, shows a cylindrical canister containing a desiccant material. Robbins ""230 does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Robbins ""230 does not show the system of baffles and mesh screens used in the present invention.
United Kingdom Patent Application Number 2 030 886 A, by Eric John Hayward dated Apr. 16, 1980, shows a filter canister for holding a granular medium for the absorption of carbon dioxide during anaesthesia. Hayward does not show the combination of a fuel filter and a desiccant bed in a single unit.
United Kingdom Patent Application Number 2 035 833, by Vaclav Sebor dated Jun. 25, 1980, shows a filter apparatus including a glass fiber filter element and a silica gel or activated carbon absorber, for filtering gases. Sebor does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Sebor does not show the system of baffles and mesh screens used in the present invention.
United Kingdom Patent Application Number 2 080 697 A, by Barry W. Dinius dated Feb. 10, 1982, shows a filter/dehydrator including water absorbing cellulosic fibers in series with a filter element. Dinius does not show the combination of a fuel filter and a desiccant bed in a single unit. Further, Dinius does not show the system of baffles and mesh screens used in the present invention. None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
The present invention is directed to a fuel filter/dryer having a casing, and the casing having an inlet and an outlet. At.least a portion of the casing is filled with a desiccant through which the fuel flows. Also within the casing, is a particulate filter which removes harmful particles from the fuel. The desiccant is of a type that changes color when saturated with water. The casing is transparent to allow the change in color to be viewed in order to ascertain whether or not the fuel filter/dryer needs replacement.
Accordingly, it is a principal object of the invention to provide a combined fuel filter and dehydrator for use in fuel systems.
It is another object of the invention to provide a combined 15 fuel filter and dehydrator having a desiccant which remains separate from the fuel.
It is a further object of the invention to provide a combined filter/dehydrator having a color-changing desiccant so that a user can readily ascertain, by inspection, whether or not the filter/dehydrator needs replacement.
Still another object of the invention is to provide a combined filter/dehydrator having a transparent casing.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.